This invention relates generally to photographic cameras and more particularly to a viewfinder mask orienting device in a camera.
While some cameras, principally twin-lens reflex cameras, are adapted to take square pictures, most present-day cameras take rectangular pictures having long and short dimensions. That is, the light beam projected by the photographic optical system toward the film is masked to form an oblong image on the film, the direction of the longer dimension of the image being either parallel or perpendicualr to the longitudinal direction of the film. An object being photographed can be photographed with its vertical direction coinciding with either the longer dimension or shorter dimension of the image projected on the film by correspondingly orienting the entire camera or by correspondingly orienting only the film holder of the camera in certain cameras.
On one hand, the orientation of the longer and shorter sides of the rectangular image observable in the viewfinder must correspond to this orientation of the image projected on the film. This presents no problem in the case of a camera which is turned between its upright state and its horizontal state for this orientation. In some cameras such as certain portrait cameras, however, only the film holder is rotated for this orientation. In such cameras, the orientation of the longer and shorter sides of the image observable in the viewfinder must be made changeable to correspond to the orientation of the film holder, that is, the film.